Drainage basin

The movement patterns of native migratory fishes may reflect different selection pressures in different environments that are associated with predictable patterns of temperature and discharge. Spatial and temporal variability in the movement patterns of adult Coho Salmon Oncorhynchus kisutch were explored with data that were collected from the Umpqua River basin, Oregon, focusing on two points in their return migration: (1) main‐stem midriver migration timing of adult Coho Salmon as they pass Winchester Dam, Oregon, and (2) adult spawn timing in tributary streams of the Smith River. Main‐stem migration of Coho Salmon as they pass Winchester Dam began 7 to 15 d after peak annual water temperature, when mean daily temperatures cooled to 18°C, but before the increases in discharge that are associated with autumn rains. Although migration timing appeared to be strongly related to river temperature, spawn timing of Coho Salmon in tributaries of the Smith River subbasin appeared to respon...

The state of Rajasthan is one of the regions of India that has scarce water resources. In the desertic terrain of the state, there are large numbers of palaeochannels that are considered to be potential aquifers for the region. However, detection and delineation of these palaeochannels is a challenging task because most of the surface signatures are obliterated by recent alluvial cover or the land use pattern. In the present study, multi-resolution, multi-temporal satellite data products from a suite of satellites such as IRS-1D, and Landsat MSS were digitally enhanced and used to detect the palaeochannels. One of the prominent palaeochannels delineated was investigated to evaluate aquifer parameters by conducting pumping tests. Pumping test data from aquifers surrounding the palaeochannel were also collected and compared in order to assess the relative groundwater prospects of the aquifer. An integrated approach which included interpretation of multi-temporal satellite data, slope variation, drainage, geomorphology and field investigation has helped to detect several palaeochannels in the study area. The study also confirms that the palaeochannel aquifer has more potential than the surrounding aquifers.

Understanding how different food resources sustain stream food webs is fundamental towards increasing our knowledge on trophic structure and energy flow pathways in fluvial ecosystems. Food webs in small mountain streams are sustained by autochthonous (instream primary production) and allochthonous (inputs from the terrestrial ecosystem) organic resources, with their relative importance highly dependent on catchment land cover. This study aimed to understand how catchment land cover determines food resource type (autochthonous, allochthonous) and quantity in mountain streams, and how this affects energy flow pathways and food web structure. We hypothesised that food resource type and quantity would reflect catchment land cover. Thus, changes in food resources would lead to shifts in macroinvertebrate assimilation of autochthonous and allochthonous food resources and consequently in dominant energy flow pathways. We further hypothesised that changes in food resources will have strong...

The assessment of natural hazards such as floods and droughts is a complex issue that demands integrated approaches and high-quality data. Especially in African developing countries, where information is limited, the assessment of floods and droughts, though an overarching issue that influences economic and social development, is even more challenging. This paper presents an integrated approach to assessing crucial aspects of floods and droughts in the transboundary Mékrou River basin (a portion of the Niger River basin in West Africa), combining climatic trends analysis and the findings of a household survey. The multivariable trend analysis estimates, at the biophysical level, the climate variability and the occurrence of floods and droughts. These results are coupled with an analysis of household survey data that reveals the behaviour and opinions of local residents regarding the observed climate variability and occurrence of flood and drought events, household mitigation measures, and the impacts of floods and droughts. Based on survey data analysis, the paper provides a per-household cost estimation of floods and droughts that occurred over a 2-year period (2014)(2015). Furthermore, two econometric models are set up to identify the factors that influence the costs of floods and droughts to impacted households.

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In this present study, Soil and Water Assessment Tool (SWAT) embedded with ArcGIS interface has been used to simulate the surface runoff from the un-gauged sub-catchments in the upper catchment of Subarnarekha basin. Model calibration and validation were performed with the help of Sequential Uncertainty Fitting (SUFI-2) in-built in the SWAT-CUP package (SWAT Calibration Uncertainty Programs). The model was calibrated for a period from 1996 to 2008 with 3 years warm up period (1996-1998) and validated for a period of 5 years from 2009 to 2013. The model evaluation was performed by Nash - Sutcliffe coefficient (NSE), Coefficient of determination (R2) and Percentage Bias (PBIAS). The degree of uncertainty was evaluated by P and R factors. Basing upon the R2, NSE and PBIAS values respectively, of the order of 0.90, 0.90 and -12%, during calibration and 0.85, 0.83 and -15% during validation, substantiate performance of the model. All uncertainties of model parameters have been well taken...

This paper presents the spatial distribution of liquid and solid (suspended load) discharge in the Ivaí River Basin, and its implication in the functioning of this river system. The Ivaí is a typical medium-size river of the basaltic plateau, the left side of the Paraná River Basin in southern Brazil. The data relating to water discharge and concentration of suspended sediment come from 19 gauging stations controlled by the former Superintendence of Water Resources and Environmental Sanitation Development – SUDERHSA, today Water Institute of Paraná. The river drains an area of 36,587 km2, and its average discharge during the study period (1974–2008) was 702.9 m3 s-1. The specific discharge (Qsp = Qm:Ab) varied uniformly between 0.01 and 0.02 m3 s-1 km2, however, an anomalous result of 0.11 m3 s-1 km2 was identified. Most of the water that enters the Ivaí River comes from the smaller sub-basins (< 500 km2), and the specific discharge from the tributaries decreases from upstream to...

This article aims at evaluating linkages between selected local traditional knowledge (LTK) indicators with meteorological drought forecasting parameters in the Mzingwane catchment area of Zimbabwe. In addition, the article investigates possible ways of integrating selected LTK indicators with the meteorological drought forecasting parameters to improve applicability of meteorological drought forecasts at local level. LTK forecast data from trees and plants for 2012/2013 season was collected through structured questionnaires administered on 40 household heads. Monthly rainfall data spanning the period September 1999-May 2013 (14 years) were used for the calculation of Standard Precipitation Index (SPI) for the study catchment. The trends in drought severity scale were then compared to the results from local traditional knowledge drought forecasting (LTKDF) to find out the degree to which they could be correlated. The GEONETCast ten day composite, SPOT VEGETATION, normalized difference vegetation index (S10 NDVI) dataset with a 1 km resolution was used to evaluate vegetation condition and hence track drought occurrence and severity. The trends in drought severity scale from NDVI were then compared to the results from LTKDF to establish the level of correlation. The analyses carried out shows a good correlation between traditional plant and tree indicators with resulting conditions captured as NDVI and SPI. The challenge on the LKDF systems, however, was lack of historical data to ensure adequate analysis and comparison with meteorological data. The study therefore recommends continuous monitoring and standardisation of LTK data.

Tobacco production in Southern Brazil has caused a profound impact in the environment, resulting in heavy sediment yields and diminishing water quality. Public programmes have attempted to address these problems by encouraging the implementation of erosion control practices. To evaluate the impact of these programmes, a small rural catchment (1.33km²) in Arvorezinha county, in the state of Rio Grande do Sul, Brazil, has been monitored since 2001. Instruments to automatically monitor flow rate and precipitation were installed in the catchment and sediment has been measured manually using a DH-48 sampler. Despite lower rainfall in 2003, there was a significant increase in the frequency of low and average flow rates, and sediment yield increased 25% in 2003 (91Mg km-2 year-1), compared with 2002 (73Mg km-2 year-1). These results can be explained by a 37.7% increase in the area dedicated to tobacco cultivation in 2003, due to a rise in tobacco prices.

Programas de conservação do solo e da água que utilizam a bacia hidrográfica como unidade de planejamento têm sido amplamente empregados. Um componente importante desses programas se refere à implantação de projetos de monitoramento hidrossedimentométrico e de qualidade de água para avaliar o impacto nos recursos hídricos das práticas introduzidas. Entretanto, em alguns casos, os resultados obtidos pelos projetos de monitoramento têm sido pouco conclusivos, devido a limitações dos procedimentos experimentais adotados. Esta revisão explora metodologias de avaliação que combinam técnicas tradicionais de monitoramento com técnicas de identificação de fontes de sedimentos que contribuem para elucidar os efeitos das práticas conservacionistas na produção de sedimentos em bacias hidrográficas e também a inter-relação dinâmica entre as fontes de sedimentos.

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

High concentrations of nitrate have been detected in streams flowing from nitrogen-saturated forests; however, the spatial variations of nitrate leaching within those forests and its causes remain poorly explored. The aim of this study is to evaluate the influences of catchment topography and coniferous coverage on stream nitrate concentrations in a nitrogen-saturated forest. We measured nitrate concentrations in the baseflow of headwater streams at 40 montane forest catchments on Mount Tsukuba in central Japan, at three-month intervals for 1 year, and investigated their relationship with catchment topography and with coniferous coverage. Although stream nitrate concentrations varied from 0.5 to 3.0 mgN L, those in 31 catchments consistently exceeded 1 mgN L, indicating that this forest had experienced nitrogen saturation. A classification and regression tree analysis with multiple environmental factors showed that the mean slope gradient and coniferous coverage were the best and se...

Ecosystems of suburban landscapes (i.e., forest, inland water ecosystem) are threatened by high nitrogen (N) loadings derived from urban air pollutants. Forest ecosystems under high chronic N loadings tend to leach more N via streams. In the northern suburbs of Tokyo, N deposition loading on terrestrial ecosystems has increased over the past 30 years. In this region, we investigated nitrate concentrations in 608 independent small forested catchment water samples from northeastern suburbs of Tokyo. The nitrate concentrations varied from 0.07 to 3.31 mg-N L−1 in this region. We evaluated the effects of N deposition and catchment properties (e.g., meteorological and topographic factors, vegetation and soil types) on nitrate concentrations. In the random forest model, simulated N deposition rates from an atmospheric chemistry transportation model explained most of the variance of nitrate concentration. To evaluate the effects of afforestation management in the catchment, we followed a m...

ÍNDICE 1. Introdução 2. Amostragem 2.1 Época de amostragem 2.2 Material e equipamento 2.3. Selecção dos locais de amostragem 2.4. Comprimento do troço a amostrar 2.5 Procedimento de amostragem 2.6 Procedimentos após amostragem 3. Processamento laboratorial 3.1 Material e equipamento 3.2 Métodos 4. Apresentação de dados 4.1 Informação relativa a capturas 4.2 Informação de fontes complementares 5. Controlo de qualidade 6. Referências bibliográficas 7. Glossário Anexo I -Ficha de campo Anexo II -Equipamento de laboratório Anexo III -Lista de espécies referenciadas para o país segundo ICN (2005) ____________________________________________________________________________________ Protocolo de amostragem e análise para a fauna piscícola -1 -

river discharge records from 30 of the world's largest river basins have been used to characterize surface hydrologic flows in relation to net precipitation inputs, ocean climate teleconnections, and human land/water use patterns. This groundwork study is presented as a precedent to distributed simulation modeling of surface hydrologic flows in large river basins. Correlation analysis is used as a screening method to classify

In this study we investigate the ability of satellite visible and infrared data to produce reliable rainfall amount estimates that could be used by hydrological models to predict streamflow for large basins. Rainfall estimates are obtained by (1) classification of clouds to raining and nonraining clouds and (2) applying a multivariate statistical model between rainfall and indices derived from the satellite observations. Satellite data corresponding to 180 randomly selected days in the period May‐September 1982–1988 are used in this study that focuses on the estimation of daily rainfall. The Des Moines River basin in the midwestern United States is the application area. The correlation coefficient between model‐predicted and rain gauge‐observed mean areal precipitation over areas of order 10,000 km2 is found to be about 0.85. In an example application the satellite rainfall estimates are used to force the operational National Weather Service hydrologic forecast model for a subbasin ...

Landslides are the most destructive natural hazards that undermine the economic and cultural development in Darjeeling Himalaya. To prepare landslide susceptibility map of the Lish River basin of Eastern Darjeeling Himalaya frequency ratio model (FRM) was applied based on remote sensing and GIS tools and an integration of ten landslide triggering parameters or factors like Geomorphology, lithology, slope angle, slope aspect, slope curvature, drainage density, NDVI, Relative Relief, land use and land cover (LULC) and soli map were made. The frequency ratio model (FRM) was used to derive class frequency ratio or class weight incorporating both pixels with and without landslides and to determine the relative importance of individual classes. All the data layers were prepared in consultation with SOI Topo-sheet (78B/9), Google earth image, Landsat 8 OLI (operational land imager), GDEM (Global Digital Elevation Model) image with the help of Arc View and ARC GIS Software (10.1). A Weighted linear combination model was performed to combine frequency ratio/class rating values and to determine the landslide susceptibility index (LSI) value on GIS software tools. Greater the value of 'LSI', higher is the propensity of landslide susceptibility over the space. Then, the Lish River basin was classified into six landslide susceptibility zones, i.e., very low, low, moderate, moderately high, high and very high considering the ranges of LSI.

The Red River is the second largest river in Viet Nam and constitutes the main water source for a large percentage of the population of North Viet Nam. Here we present the results of an annual survey of Escherichia coli (EC) and Total Coliforms (TC) in the Red River basin, North Viet Nam. The objective of this work was to obtain information on faecal indicator bacteria (FIB) numbers over an annual cycle and, secondly, to determine the die-off rates of these bacterial indicators. Monthly observations at 10 stations from July 2013-June 2014 showed that TC and EC reached as high as 39100 cfu (colony forming units) 100 ml(-1) and 15300 colonies 100 ml(-1), respectively. We observed a significant seasonal difference for TC (p < 0.05) with numbers being higher during the wet season. In contrast, no significant seasonal difference was found for EC. The FIB die-off rates ranged from 0.01 d(-1) to a maximum of 1.13 d(-1) for EC and from 0.17 d(-1) to 1.33 d(-1) for TC. Die-off rates were ...

Sediment cores were collected at the outlet of the highly anthropogenized catchment of the Seine River at two contrasting sites: a flood plain of the lower Seine River and a quasi-permanently submerged harbour basin (or wet dock) in the upper tidal estuary. Analyses of artificial radionuclides ( 137 Cs and plutonium isotopes), coupled with hydrological and bathymetric data, lead to a precise dating of the sediment cores collected at the two sites. 137 Cs signals originating from global fallout (early 1960s) and from the Chernobyl accident (1986) are identified, but at different levels due to the incomplete nature or variable continuity of the records. Anomalous 238 Pu concentrations found at both sites (1e2 Bq kg À1 ) are attributed to unknown industrial releases originating from upstream. Interpolating 137 Cs sediment activities under the assumption of a constant sediment rate, those releases were dated back to 1975 AE1, thus providing a local but reliable time-marker. Age models have highlighted a very contrasting sediment filling dynamics in these two sites. This study presents the first sediment record of alpha-and gamma-emitting artificial radionuclides obtained at the outlet of the huge catchment area of the River Seine, over a period covering the last 50 years.

Hydrological information is essential for adequate water resources management as well as for water supply, energy supply, water allocation, among other services. However, this information does not always exist in quantity and quality to be used in hydrological or water management studies, and alternative methods are required to estimate minimum flows. Estimation based on homogeneous regions enables to transfer observation data from a known location to a location without data, but in the same region. Since the fluviometric stations in the state of Goiás (Brazil) are not uniformly distributed, the present work aimed at delimiting homogeneous regions of minimum flows, using the cluster grouping method with the K-means algorithm.Thus, 71 fluviometric stations with at least 5 years of continuous data were selected, obtained from the HIDROWEB system. In addition to the observed data, other variables were considered, such as drainage area, perimeter, specific minimum flows Q7,10, Q90, Q95 and average slope. The use of all these variables together with the observed data made it possible to determine,with great accuracy, 5 homogeneous regions of minimum flows based on the cluster analysis, enabling to obtain the minimum flows of reference for each region.In the selected homogeneous regions, it was possible to observe that the regions with the highest values of average slope presented smaller minimum flows, and the same could be observed under inverse conditions, i.e., lower values of average slope had higher minimum flows.It is also noteworthy that river monitoring is deficient in the center-south and center-north parts of the state of Goiás, making water resources management difficult. This fact indicates, therefore, the need to expand the river monitoring system throughout the state, especially in its southern and northern regions.

The main objective of the research is to set a transboundary water management system for the Blue Nile River Basin (within its 16 sub-basins) as well as to create calibrated satellite rainfall data for the Blue Nile River Basin (BNRB). Within the Water Evaluation and Planning (WEAP) model, the simplified rainfall-runoff option has been adopted to determine the runoff of the BNRB, using calibrated satellite rainfall data and adjusted monthly evapotranspiration factors. The WEAP model has been calibrated for the period (1980-1995) and validated for the period (1996-2010) where the simulated and observed flows have been compared at Eldeim, Giwisi, Hawata and Khartoum stations in a monthly time step yielding reasonable values. The results have effectively showed that the simulated flows are reasonable using the Nash-Sutcliffe efficiency criteria (r 2 ) and the Coefficient of Determination (d) of the model performance. The research has found that unmet demands for water resources projects in BNRB may reach more than 50%, especially when considering a high priority for all water resources projects in the basin for all suggested scenarios. For a better BNRB management between Sudan and Ethiopia, it is required to define the priority order for each project within the Basin and to determine allocations of supplies and demands for these projects. The above cannot be achieved without a strong cooperation reaching between riparian countries in place that eventually lead to joint operation of the large storage structures, such as GERD, Karadobi and Mendaya dams.

Precipitation is of extreme importance for the management of water resources, since it is a question of degraded areas and with deforestation for deforestation and the withdrawal of firewood. Frequency analysis was performed on the annual rainfall totals by drawing up the graphs. The scale proposed by Meis et al. (1981), and by the meteorological and CPTEC/INPE nuclei, and provided by Xavier et al. (2005), the annual values ​​that approached the mean value were characterized as intermediaries, and in the scale of annual precipitation values, those that moved away 25% away from the average were considered as very rainy years, and below 25%, like dry years. The application of the Student's t test of significance, pointed out that precipitation data in general are 99% significant. The results showed a tendency of reductions in the rainfall indices, with oscillations of precipitations throughout the series 1962 to 2019, and evidenced the recurrence of maximum values ​​of annual prec...

The fish fauna of eight streams with different land uses of their watersheds (forested and rural areas) in the lower Iguaçu River basin was inventoried, in order to evaluate the composition and species richness. The fishes were sampled quarterly from May 2015 to February 2016, using the electrofishing technique. In total, 4,239 individuals were captured, belonging to six orders, 11 families and 26 species. The orders Siluriformes and Characiformes, and the families Characidae and Trichomycteridae were the most specious. Of the total species sampled, 65% were endemic to the Iguaçu River basin, four are not described and four are non-native. As expected to the Iguaçu River basin, the inventoried fauna revealed low richness and high endemism, however was highly nested within the species composition reported for main channel of Iguaçu River and their larger tributaries. The species recorded here corresponded to a subset of 24.5% of the 106 species documented for the basin. The streams p...

Dams are the major source of water for irrigation in India. As a result, any variability in rainfall over the catchment area of dams leads to huge economic loss. It also triggers water-sharing conflicts. Hence, understating the variation in rainfall in association with dams becomes essential. For the present study, the upper Godavari basin, primarily representing the semiarid region in India, is selected. To understand the rainfall variation, the Mann-Kendall trend test is employed after checking the homogeneity of the data. Using the inverse distance weighted technique, the monthly, seasonal and annual trends in rainfall are interpolated. These interpolated results are then superimposed over the location of the dams. The results depict that the rainfall decreases in June, while it increases in August for most of the stations. The highest increase in monsoon rainfall is experienced in Akole (11.7 mm/year), while Khuldabad has experienced the maximum decline (-6.58 mm/year) in rainfall. When the spatial variability of annual rainfall is considered, it is mostly declining in the eastern part of the basin. This area of decreasing rainfall accounts for more than 35% of the total basin area. Around 34 dams with capacity of more than 0.5 MCM (million cubic meter) are situated here. As a result of declining rainfall, the water supply from these dams might get adversely affected. Hence, for the upper Godavari basin, based on the rainfall variability analysis, policies should focus on demand side management of water resources.

Gorges and bedrock channels are always the sites of interest for studying fluvial processes. The response and adjustment of the flow to lithological and structural control are also the causes of the several focused studies of bedrock channel. The bedrock channel in the present study also reveals the response to bedrock lithology. The bedrock channel incision affects the evolution of the channel forms while the shapes, size, gradient and plan form of the rocky channels are largely determined by the physical characteristics of bedrock (structure, jointing, resistance to erosion, etc.) rather than the hydraulics and sediment transport characteristics. Since the width and depth of the Kas River George are almost constant therefore the velocity of discharge increases. Hence, the energy available for stream work will be greater in the segments of gorge even at normal flow discharge. Increased velocity helps to maintain the material transportation and/or increases the intensity of erosion ...

Dams are the major source of water for irrigation in India. As a result, any variability in rainfall over the catchment area of dams leads to huge economic loss. It also triggers water-sharing conflicts. Hence, understating the variation in rainfall in association with dams becomes essential. For the present study, the upper Godavari basin, primarily representing the semiarid region in India, is selected. To understand the rainfall variation, the Mann-Kendall trend test is employed after checking the homogeneity of the data. Using the inverse distance weighted technique, the monthly, seasonal and annual trends in rainfall are interpolated. These interpolated results are then superimposed over the location of the dams. The results depict that the rainfall decreases in June, while it increases in August for most of the stations. The highest increase in monsoon rainfall is experienced in Akole (11.7 mm/year), while Khuldabad has experienced the maximum decline (-6.58 mm/year) in rainfall. When the spatial variability of annual rainfall is considered, it is mostly declining in the eastern part of the basin. This area of decreasing rainfall accounts for more than 35% of the total basin area. Around 34 dams with capacity of more than 0.5 MCM (million cubic meter) are situated here. As a result of declining rainfall, the water supply from these dams might get adversely affected. Hence, for the upper Godavari basin, based on the rainfall variability analysis, policies should focus on demand side management of water resources.

Th e purpose of this study was to obtain and prove the methods of catchment regionalization in case of annual maximum fl oods. Identifi cation of Polish rivers was hold on the basis of regional frequency analyses including recognition of homogenous regions in their physical properties and river fl ow parameters. Results indicate the division on two regional groups: mountain and lowland catchments. Statistical tests prove the obtained regionalization and allow calculating the regional probability curves for these two catchment groups. Obtained results may be helpful in the analysis of fl oods in ungauged catchments and these where hydrological observations were held in a short period especially when dependency of the maximum probable fl ows in analysed catchments from their physico-geographical features was proved. Słowa kluczowe: przepływy maksymalne roczne prawdopodobne, analiza częstotliwości regionalnej, wezbranie, czas powtarzalności, typologia zlewni Key words: annual probable maximum fl ow, regional frequency analysis, fl ood, return period, typology of a basin WSTĘP Metoda analizy regionalnej częstości wezbrań znajduje zastosowanie wówczas, gdy brakuje danych hydrologicznych niezbędnych do oszacowania parametrów wezbrania w zadanym czasie lub informacja, którą dysponujemy jest nie-* e-mail:

The purpose of this study was to obtain and verify the methods of catchment regionalization for annual maximum discharge. An identification of Polish rivers was performed based on regional frequency analyses including recognition of regions homogeneous with respect to their physical properties and river flow parameters. The results suggest a division into two regional groups: mountain and lowland catchments. Statistical tests verify the regionalization obtained and allow to calculate regional probability curves for these two catchment groups. The results obtained may be helpful in the analysis of floods in ungauged catchments and in those where hydrological observations were performed during a short period, especially when the dependence of the maximum probable flows on their physico-geographical features in catchments under analysis has been proved.

The present study compared the performance of two different models for streamflow simulation namely: Soil Water Assessment Tool (SWAT) and the Artificial Neural Network (ANN). During the calibration periods, the Nash-Sutcliff (NS) and Coefficient of Determination (R2) for SWAT was 0.74 and 0.81 respectively, whereas for ANN, it was 0.99 and 0.85 respectively. The ANN performs better during the validation period as the result revealed with NS and R2 having 0.98 and 0.89 respectively, while for the SWAT model it was 0.71 and 0.74 respectively. Based on the recommended comparison of graphical and statistical evaluation performances of both models, the ANN model performed better in estimating peak flow events than the SWAT model in the Upper Betwa Basin. Furthermore, the rigorous time required and expertise for calibration of the SWAT is much less as compared with the ANN. Moreover, the results obtained from both models demonstrate the performances of the models in terms of NS and R2 and other model performance indices were satisfactory. Hence, the ANN (black-box model) might emerge as a faster model to implement on water resources management especially in data scarce basins.

In the Kirama-ara River basin, Matara, southern region of Sri Lanka, a variety of agricultural inputs are utilized, and flooding is a common hazard. As a result, the complete physicochemical profile of the groundwater in the Kirama-ara river basin is yet undiscovered. Therefore, the goals of this study were to (a) identify the geochemical characteristics and changes in water quality, (b) evaluate non-carcinogenic health risk and develop a GWQI, and (c) generate a spatial distribution map for groundwater physicochemical parameters in the Kirama-ara river basin in Matara, Sri Lanka. The physiochemical characteristics of 16 groundwater samples, including pH, electrical conductivity (EC), total dissolved solids (TDS), Na + , K + , Ca 2+ , Mg 2+ , Cl -, NO3 -, PO4 3-, and SO4 2-, were examined for spatial and temporal variations. The pH, NO3 -, and PO4 3-values of 50%, 6.25%, and 12.5% of the samples, respectively, were determined to be beyond the allowable limit by both the WHO and SLS. The physicochemical investigation demonstrates that while 87.5% of the locations were acceptable for drinking, 12.5% of them lacked sufficient amounts. The most common hydrochemical facies were Ca 2+ -Mg 2+ -HCO3 -, mixed Ca 2+ -Mg 2+ -Cl -face, and Ca 2+ -Cl -. Rock weathering has a profound impact on the ionic composition and chemistry of groundwater. Additionally, health risk assessment research conducted in accordance with United States Environmental Protection Agency rules revealed that children face greater health risks than adults. To build reasonable management plans for long-term groundwater quality conservation and public health, more research is required.

In the Kirama-ara River basin, Matara, southern region of Sri Lanka, a variety of agricultural inputs are utilized, and flooding is a common hazard. As a result, the complete physicochemical profile of the groundwater in the Kirama-ara river basin is yet undiscovered. Therefore, the goals of this study were to (a) identify the geochemical characteristics and changes in water quality, (b) evaluate non-carcinogenic health risk and develop a GWQI, and (c) generate a spatial distribution map for groundwater physicochemical parameters in the Kirama-ara river basin in Matara, Sri Lanka. The physiochemical characteristics of 16 groundwater samples, including pH, electrical conductivity (EC), total dissolved solids (TDS), Na+, K+, Ca2+, Mg2+, Cl−, NO3−, PO43−, and SO42−, were examined for spatial and temporal variations. The pH, NO3−, and PO43− values of 50%, 6.25%, and 12.5% of the samples, respectively, were determined to be beyond the allowable limit by both the WHO and SLS. The physicoc...

O objetivo deste trabalho é contribuir para avançar no conhecimento acerca do potencial do Modelo HAND para avaliação e monitoramento da expansão urbana da Região Metropolitana de Porto Alegre (RMPA) em áreas suscetíveis à inundação. Como procedimento metodológico foi utilizada a combinação de imagens de iluminação noturna com índices de vegetação NDVI do satélite Landsat. Para identificar as áreas suscetíveis à inundação, foi utilizado o Modelo HAND. Foi identificado um aumento de 22,15% da área urbana ocupada entre os anos 1985 e 2015. Com o Modelo HAND foi possível identificar que as novas ocupações urbanas estão situadas em cotas de até 2 metros de elevação em relação à drenagem mais próxima. Este dado evidencia que áreas identificadas como de expansão estão localizadas em cidades problemáticas do ponto de vista de inundações.

A comprehensive research program was conducted to enhance understanding of the hydrologic and phosphorus movement relationships of flat, sandy, high-water-table soils pervasive in the Kissimmee River Basin Region of Florida which drains into Lake Okeechobee. This region generates high phosphorus loads into the lake relative to other basins, causing environmental concerns. Field instrumentation and monitoring wells were installed at four experimental pasture sites in the Kissimmee River Basin to conduct research concerning water and phosphorus movement in fiat, sandy, high-water-table soils. The focus was to obtain hydrologic/water quality data sufficient to determine surface/subsurface flow partitioning, and thus phosphorus flowpaths from the land phase to stream channels. A field-scale model was developed to simulate water and phosphorus movement from individual fields. This model, named FHANTM, is based on DRAINMOD with modifications to include simulation of phosphorus movement and routing of overland flow. The field monitoring data were used to calibrate and verify the modified model. This model was developed for use in predicting the effects on phosphorus movement to streams from application of management practices on the dairies.

A comprehensive research program was conducted to enhance understanding of the hydrologic and phosphorus movement relationships of flat, sandy, high-water-table soils pervasive in the Kissimmee River Basin Region of Florida which drains into Lake Okeechobee. This region generates high phosphorus loads into the lake relative to other basins, causing environmental concerns. Field instrumentation and monitoring wells were installed at four experimental pasture sites in the Kissimmee River Basin to conduct research concerning water and phosphorus movement in fiat, sandy, high-water-table soils. The focus was to obtain hydrologic/water quality data sufficient to determine surface/subsurface flow partitioning, and thus phosphorus flowpaths from the land phase to stream channels. A field-scale model was developed to simulate water and phosphorus movement from individual fields. This model, named FHANTM, is based on DRAINMOD with modifications to include simulation of phosphorus movement and routing of overland flow. The field monitoring data were used to calibrate and verify the modified model. This model was developed for use in predicting the effects on phosphorus movement to streams from application of management practices on the dairies.

Abundances and distributional changes of branched glycerol dialkyl glycerol tetraethers (brGDGTs) in fluvially influenced sediments are used in various paleoclimate studies to reconstruct variations in soil export, continental air temperature and soil pH in corresponding river basins. For accurate interpretation of these records, it is important to understand the provenance and the evolution of biomarker signals as they move through the river system. Here we investigate the brGDGT composition of modern river sediments of the Danube River, the second largest river in Europe. BrGDGT-based mean annual air temperature and soil pH parallel the actual values of air temperature and soil pH from the upper to the lower basin, showing that signals predominantly reflect local as opposed to basin-wide environmental conditions. Furthermore, data generated using the recently developed method with improved chromatography, separating the 6-methyl-isomers from the 5-methyl-isomers, was compared with that resulting from the conventional method. We show that the temperatures and pH values reconstructed using the data obtained by improved chromatography best resemble the local environmental conditions throughout the Danube River basin. Our results highlight the importance of in-depth studies within river systems to better understand the provenance of biomarker signals in fluvially derived sedimentary archives.

Abundances and distributional changes of branched glycerol dialkyl glycerol tetraethers (brGDGTs) in fluvially influenced sediments are used in various paleoclimate studies to reconstruct variations in soil export, continental air temperature and soil pH in corresponding river basins. For accurate interpretation of these records, it is important to understand the provenance and the evolution of biomarker signals as they move through the river system. Here we investigate the brGDGT composition of modern river sediments of the Danube River, the second largest river in Europe. BrGDGT-based mean annual air temperature and soil pH parallel the actual values of air temperature and soil pH from the upper to the lower basin, showing that signals predominantly reflect local as opposed to basin-wide environmental conditions. Furthermore, data generated using the recently developed method with improved chromatography, separating the 6-methyl-isomers from the 5-methyl-isomers, was compared with that resulting from the conventional method. We show that the temperatures and pH values reconstructed using the data obtained by improved chromatography best resemble the local environmental conditions throughout the Danube River basin. Our results highlight the importance of in-depth studies within river systems to better understand the provenance of biomarker signals in fluvially derived sedimentary archives.

The study presents the Environmental Flow Assessment (EFA) model on sustainability planning strategies to reduce damage in the main area of Kenyir Lake Basin. The XPSWMM model have been used to simulate the EFA in this study. Based on simulation in the Terengganu River, which has a most effective discharge of 42.78 m 3 /s with depth on 3.94 m and a water velocity of 0.54 m/s, which are expected to meet the development needs of fish species, the analysis for both study rivers found the minimum river discharge values with the frequency probability in the period of 20 years needs to be maintained. While, based to the simulation in the Petuang River, the maximum discharge is only 0.08 m 3 /s, the maximum depth is 0.4 m, and the maximum water speed is 0.04 m/s, which is adequate for a small number of small-sized fish species. With output deficiency of less than 20% from an actual situation, the two lowest values later obtained were adopted as input in low flow analysis. A more effective management approach ensures the ecosystem's sustainability and maintains an optimal equilibrium among the many uses. Environmental flows aren't considered a luxury but instead an integral component of contemporary water management given the global misuse of water resources and the resulting degradation of ecosystems and their functions. It is a strategy that requires widespread adoption.

Typical disaster flooding and flash floods in Malaysia. Floods occur especially during the wet season within the geographical region area which is especially influenced by the northeast monsoon. So the sampling study was conducted in March 2019 in normal season. Cross-sectional measurements involving the measurement of river width, river depth and velocity were conducted at both sampling times. The main objective of this study was to identify the pattern of rainfall distribution and river discharge rate in the River Basin Relative when the flash flood event occurred. The average seasonal discharge value in the normal Relau River (Upstream) is 0.04 m3s-1, Relau River (Midstream) is 0.57 m3s-1, Relau River (Downstream) is 0.35 m3s-1. Whereas for Ara River (Midstream) is 0.78 m3s-1, Ara River (Downstream) is 0.19 m3s-1) and Kluang River (Upstream) is 0.18 m3s-1. The estimated value for flash flood shows that total water and sewer capacity that occurred during the flash floods was to in...

Kenyir Lake Basin was built to generate hydroelectric power for Peninsular Malaysia. This water body is a promising natural preserved environment and has been attracting the developer to develop tourist spots to fulfill their profit margin. Such approach commonly has been polluting the environment since the past few decades. In the present study, the hydrological and water quality assessment on rivers was carried out to identify the existing physical environment of Kenyir Lake Basin. Samples and in-situ data were collected at 19 stations during the dry and wet season. The obtained data was compared with National Water Quality Standard (NWQS) for Malaysian waters as well as interpreted and analysis using chemometrics technique. Based on the climatology and hydrological data, it has been observed that the sedimentation rate is increasing which may damage the Kenyir Dam turbines in the future. Besides that, the water quality of Kenyir Lake Basin is complied to Class IIB NWQS which is suitable for recreational use with body contact. Similarly, Kenyir Lake Basin is classified as Class III based on Malaysian Department of Environment (DOE) water quality index; which is suitable for body contact recreational activities but requires an extensive treatment. The chemometrics analysis has highlighted total dissolved solid, turbidity (TUR), biological oxygen demand, chemical oxygen demand and salinity have affecting the water quality. Additionally, dissolved oxygen and pH showed higher potential risk toward the environmental process management and monitoring owing to the development surround Kenyir catchment area. The present findings advocate a higher management method to facilitate the preservation and maintain the life of Kenyir Lake Basin.

The climate changes caused by changing of water level. This study was carried out at Teren season to assess the sedimentation problem and its characteristic. Three parameters the correlation matrix and linear regression methods. The TSS (mg/L) SSC (mg/L) were higher during dry season compared Journal of Fundamental and Applied Sciences

This study is aimed to look at the level of water quality deterioration in Terengganu River Basin. Environmental management studies on the deterioration of water quality in Terengganu River Basin have been using data collection and analysis methods. The Gravimetric method was used to analysis the TSS measured in mg/L. 250 ml water samples was needed for each study area (each station). All preparation and preservation of the samples are in accordance with standard procedures provided by the American Public Health Society (APHA) and United States Environmental Protection Agency (USEPA). The results show that Terengganu River Basin is classified in level III that is contaminated. The Terengganu River Basin is contaminated at the downstream to the middle of the river due to anthropogenic activity. Moreover, the results indicate that the amount of AN and TSS is higher and is a major contributor to the deterioration of water quality in the Terengganu River Basin. Management of water resou...

Water resource management is important for human well-being, ecosystems development and protection of existing water bodies from pollution and exploitation. Water resource management and sedimentation are carried out in Terengganu River Basin, Terengganu. The main objective is to study water resources management on sediment problems in the Terengganu River Basin. The Gravimetric method was used to analysis the TSS measured in mg/L. 250 ml water sample was needed for each study area (each station). Based on the cross section trend and the average downstream and middle section of the Sungai Terengganu system, the average TSS level is higher than the upper section. The minimum width allocation of river reserves to control development near the river is based on the Department of Irrigation and Drainage (DID). Finally, there are a few recommendations of sedimentation management around Terengganu River Basin that will improve the river water quality, especially in Malaysia. 

Water is a vital for all aspects of human and ecosystem survival. The evaluations of water quality parameters and hydrological status are necessary to enhance the performance of an assessment operation and develop better water resources management and plan. There are three sampling stations were selected along the Kuantan River. Seven water quality parameters were measured and Malaysian Department of Environment Water Quality Index (DOE-WQI) was calculated and classified based on the National Water Quality Standard, Malaysia (INWQS). The water balance status applied to determine the stability of inflows and outflows into and from the basin. As a result, all water quality parameters (DO, COD, BOD, TSS, NH3-N and pH) which categorized under the ranged of class II until class IV respectively. Kuantan River located in Pahang state, Malaysia which is significantly degrading due to human activities as well as urbanization in and within the area. Overall, the result showed that the estimat...